1. Technical Field
The present invention relates to a sewer and drain cleaning apparatus of the type adapted to unwind a cable or snake from a rotary drum and feed the cable through a drain. More particularly, the present invention relates to a drain cleaning apparatus which readily permits lo interchange of rotary drums.
2. Background Art
Drain cleaning machines typically have a rotary drum which contains a coiled cable or snake. To clean a drain, the drum is rotated and a length of cable is advanced by a control from the drum and fed through the drain to clear an obstruction. An exemplary cable control is disclosed in U.S. Pat. No. 3,394,599, issued Jul. 30 1968, and owned by the assignee hereof. After the drain is opened, the cable is withdrawn from the drain and wound back into the drum. A drain cleaning machine may have 125 feet of cable and can weigh more than 300 pounds, with the weight of the cable and the drum accounting for than one-half of the total machine weight. Due to their substantial weight, drain cleaning machines sometimes have a wheeled frame for transporting the machine to and from a job site.
When, in the course of cleaning a drain, the entire length of cable is drawn from the drum and fed into a drain without reaching the obstruction, additional cable must be attached to the trailing end of the original cable and fed through the drain.
One approach to increasing the length of a cable is to manually load a new cable into an emptied drum and attach the free end of the new cable to the trailing end of the original cable. Feeding of the lengthened cable into the drain then is resumed. The problem with reloading a drum, in addition to the unacceptable amount of time required and the inconvenience of transporting a cable to the job site, is that upon clearing the obstruction, the entire loading procedure must be repeated in reverse when the cable is withdrawn from a drain to permit the original cable to fit within the drum.
Some drain cleaning machines have a removable drum. When the entire length of the cable is drawn from the original drum and it is desired to increase the cable length, the cable is disconnected from the drum and the original drum is replaced with a second, preloaded drum. The original cable then is connected to the new cable and operation is resumed.
Removable drums also are used to facilitate the interchange of different sizes of cables on a drain cleaning machine. That is, when the gauge or length of a cable on a drain cleaning machine is unacceptable for a particular drain cleaning application, the original drum and cable are removed from the machine and replaced with a drum which contains a cable having a suitable size. By maintaining a supply of replacement drums each of which are preloaded with a different size of cable, the proper size cable easily and rapidly can be installed on a drain cleaning machine.
The problem with drain cleaning machines which have a removable drum is the difficulty in safely handling the weight of the drum and a cable. When increasing the length of a cable, the emptied drum first must be dismounted and transported from the machine. The replacement drum and cable then must be transported to the already positioned machine and mounted thereon. To change the size of a cable, the loaded original drum must be dismounted and the replacement drum and cable must be delivered and mounted on the machine. Due to the weight and generally cumbersome nature of a drum and a cable, removal and replacement of a drum requires a considerable amount of time and heavy lifting. Consequently, the need exists for a drain cleaning machine that facilitates the interchange of a rotary drum and cable.